Toothbrushes have handles that are generally formed of a relatively durable material that lasts longer than the brushing bristles. In fact, the American Dental Association recommends replacing toothbrushes every 3-4 months (or even more frequently) because the bristles typically become frayed and worn with use, resulting in a decrease in cleaning effectiveness. In addition, improved oral hygiene is promoted through toothbrush replacement. Since germs may breed in the bristle section, regular replacement of toothbrushes (preferably at least every 3-4 months) greatly reduces germ accumulation and transmission from bacteria-encrusted bristles.
A cost-effective alternative to purchasing a new toothbrush is the replacement of only the cleaning portion of the brush. It may be particularly desirable to replace only the head or brush sections if, for instance, the handle or gripping section is costly (e.g., made from an expensive material), or if the handle or gripping portion has an ornamental design (which the user would like to keep using).
One type of toothbrush with an expensive handle is a powered or electric toothbrush. Powered or electric toothbrushes (hereinafter, “power toothbrushes” for the sake of convenience, without intent to limit) have been available for some time, and are becoming increasingly popular with both adults and children. Power toothbrushes have advantages over manual (non-powered) toothbrushes in that they may impart movement to the bristles at much higher speeds than possible manually. Such toothbrushes also may impart different types and directions of motion, and/or other functionalities. The various motions, generally in combination with manual movement of toothbrush by the user, are commonly viewed as providing superior cleaning than manual toothbrushes.
Known power toothbrushes include a brush head with a bristle carrier portion that moves (rotates, oscillates, vibrates, etc.) in some manner so as to clean the teeth. The bristles, which typically comprise bristle tufts, are generally uniform with one end fixed into the bristle carrier portion and the other end free to contact the surface of the teeth while brushing (the free, cleaning ends of the bristles). The free ends of the various tufts present a surface envelope that is capable of some deformation when the bristles bend. When in contact with the tooth surface to be brushed, the bristles may deform so that the surface envelope tends to conform to the complex surface of the teeth.
Power toothbrushes which emit light or generate other emissions from one or more electrically powered elements disposed in the head of the toothbrush, or other area remote from the head, are also known. Emissions from the electrically powered elements in the head of the toothbrush may be transmitted from elements such as light-emitting diodes (LEDs) or fiber optics. Examples of such toothbrushes are described, for example in United States published patent application 2010/0178252 to Sagel et al., entitled “Products and Methods for Disclosing Conditions in the Oral Cavity,” and assigned to The Procter & Gamble Company Intellectual Property Division; United States published patent application 2005/0066459 to Pinyayev et al., entitled “Electric Toothbrushes and Replaceable Components,” and assigned to The Procter & Gamble Company Intellectual Property Division; U.S. Pat. No. 7,422,598 to Altshuler et al., entitled “Multi-Wavelength Oral Phototherapy Applicator,” and assigned to Palmoar Medical Technologies, Inc.; U.S. Pat. No. 7,354,448 to Altshuler et al., entitled “Dental Phototherapy Methods and Compositions,” and assigned to Palmoar Medical Technologies, Inc.; U.S. Pat. No. 7,329,274 to Altshuler et al., entitled “Conforming Oral Phototherapy Applicator,” and assigned to Palmoar Medical Technologies, Inc.; U.S. Pat. No. 7,329,273 to Altshuler et al., entitled “Tissue Penetrating Oral Phototherapy Applicator,” and assigned to Palomar Medical Technologies, Inc. The electrically powered element can be disposed on or in the head of the toothbrush. However, the power element must be of a size and placement such that space remains for bristles and the mechanical components of the power toothbrush. Mechanical components used to convey motion to the bristles typically consume much of the space available within the head and neck of the toothbrush. Increasing the size of the head and/or handle of the toothbrush to increase space for including the electrically powered element results in a toothbrush that is commonly felt to be too large to effectively and comfortably clean the surfaces of the oral cavity, and is generally avoided in most designs.
As noted above, it is desirable to form a power toothbrush with a replaceable head as a cost-effective alternative to the purchase of a new power toothbrush when the bristles are worn and/or softened and do not perform as effectively as desired. Preferably, the main unit of the power toothbrush may be used well after the bristles of the first toothbrush head have been worn out, and toothbrush heads may be replaced as needed while still using the original main unit. In power toothbrushes with energy sources disposed in the head, the replaceable head may be formed to contain the energy source. However, a more cost-effective alternative is a replaceable head that accommodates an energy source that remains coupled to the main unit (rather than remaining with the replaceable head). Cost savings are realized by not replacing the energy source and by the reduction of material needed in the replaceable head. Examples of such replaceable heads are shown in the above-noted United States patent publications 2010/0178252 and 2005/0066459 and in the UltraBlu™ toothbrush sold by TechLight Systems, Inc., of Florida (see http://www.ultrablu.net/).
Another desire for a replaceable head is ease of replacement. Means of attachment in prior art replaceable heads include such connections as interference fits, and snap-on, screw-on, and dovetail connections. Ease of replacement may be complicated in replaceable heads that accommodate energy source coupled to the main unit because of the need to couple the replaceable head with the energy source in a particular manner, and because the energy source may interfere with certain movements necessary to couple the replaceable head with the main unit. For instance, an energy source as shown in the above-noted United States patent publications protrudes from the main unit so that a dovetail connection requiring sliding of the replaceable head with respect to the head of the main unit is not feasible. It would be desirable to provide a replaceable head for a power toothbrush that accommodates the energy source disposed on the toothbrush head (such that the mechanics of the toothbrush are not interrupted or otherwise compromised) and which also facilitates removal and replacement of the replaceable head.